Method of, and arrangement for, producing a fixing means

ABSTRACT

The invention relates to a method of, and an arrangement for, producing a fixing means, for example in the form of a touch-and-close fastener part, comprising: the formation of a carrier structure ( 10 ) which is provided with stem-like fixing elements ( 12 ) which are connected to one another at least in pairs, via an intermediate element ( 14 ), to form a cramp-like, in particular U-shaped, fixing part ( 16 ), wherein the stem-like fixing elements ( 12 ) engage through the carrier structure ( 10 ) and project beyond the same, and the intermediate element ( 14 ), which extends between those fixing elements ( 12 ), is arranged on the carrier structure ( 10 ), and wherein the respective fixing part ( 16 ) is introduced as a whole into the carrier structure ( 10 ), which, for this purpose, is designed in the form of a cramp-like, in particular U-shaped, moulding prior to introduction.

The invention relates to a method of, and arrangement for, producing a fixing means, for example, in the form of a touch-and-close fastener part, comprising the following:

-   -   formation of a support structure which is provided with         stem-like fixing elements which are connected to one another at         least in pairs by way of an intermediate element with the         formation of a cramp-shaped, in particular U-shaped, fixing         part, the stem-like fixing elements extending through the         support structure and projecting over it and the intermediate         element which extends between these fixing elements being         located on the support structure.

EP 1 047 539 B1 discloses a molding process for producing fastening articles in addition to a process for implementing the process. In the known solution, in a first step, a premolding element as the support structure is formed in the mold cavity of an injection molding machine, which cavity is defined by the first and second parts of a mold. In this molding process, on one side of the support structure, a plurality of stem-like fixing elements are formed and at least one connecting means, with which the premolding element completed later can be fixed on other components, is molded onto the opposite back side of the support structure.

In another production step, the first part of the mold is then removed in order to expose an arrangement of stem-like fixing elements as so-called mold elements, while in other respects the indicated premolding element as the support structure remains in the second part of the mold. Then, in a subsequent molding process, permanent deformation of the stem-like fixing element is induced, for example using heat and pressure in order in this way to generate head-like fastener elements in the manner of a mushroom fastener on the free ends of the stem-like fixing elements. The number of fixing elements to be mounted on the support structure in the known solution encounters its limits where the mold tool with its mold cavities to be provided for the stem-like fixing elements has its corresponding wall boundaries.

U.S. Pat. No. 4,290,174 discloses a generic process in addition to a device for producing a fixing means. In the production process disclosed in FIG. 6 of the U.S. patent, two belt-like support structures are unwound opposite from storage rolls and delivered to a conveyor machine with two opposing drivable support belts, with a top and a bottom strand. Via a thread supply means with a plurality of channels a corresponding plurality of monofilament threads are supplied to the indicated conveyor and transport means and are connected in alternation by means of two tacking means of the threads to the film-like heated support structure, in this respect by the monofilament threads in alternation being pressed into the pertinent strip material running between the two support structure-film lengths.

Within the conveyor and transport means, oppositely along the upper and lower strand, the lengths of film are then guided as the support structure; said lengths of film have the monofilament threads in place between themselves and are held on one another in this way. After running through the conveyor and transport means, a longitudinal cutting means is used to cut the respective monofilament threads which are braced between the support structures approximately in the middle so that then two lengths of the support structure which are separated from one another are present and can be taken up onto removal rolls for further processing. The respective strip-like support structure is then characterized in that cramp-shaped, in particular U-shaped, fixing parts are fastened in the structure on the peripheral side with surrounding material portions, so that only the stem-like fixing elements protrude from the support structure which otherwise, after the cutting process and before take-up, are brought into the interlocking head shape by a singeing means. The alternating squeezing or molding of the monofilament threads at the entry of the conveyor and transport means, however, leads to problems of process reliability so that, on the whole, this production process may be difficult to manage.

The known fixing means are used, in conjunction with another fixing part which is provided, for example, on its top with a loop-shaped structure, especially to form a detachable touch-and-close fastener by the hook elements extending under the head parts of the stem-like fixing elements in order to thus enable a plurality of opening and closing processes. These fixing elements are generally used in the clothing and in the diaper industry; but they are increasingly also being used in technical applications, whether in the area of cable connectors, or in the automotive or other vehicle industry to be able to fasten the corresponding components to vehicle structures.

On the basis of this prior art, the object of the invention is to devise a process and the respective device for producing a fixing means such that process reliability with a high degree of production quality for the product is achieved and a high level of production speed is ensured in order to cut production costs. This object is achieved by a process for producing a fixing means with the features of claim 1 in its entirety and a device for implementing the process with the features of claim 8.

The invention is characterized by the introduction of the respective fixing part as a whole into the support structure which is made cramp-shaped, in particular U-shaped, for this purpose as a molded part before introduction, a type of shooting means with very high production speeds joining the respective fixing part to the support structure. In spite of the high production speeds which are surprising in this respect, it is surprising for one with average skill in the art in the field of production of touch-and-close fastener parts that he acquires a very high product quality with a negligible scrap rate.

If the support structure which is to be provided with the cramp-shaped, in particular U-shaped, fixing parts is still soft, that is to say, in this respect is at least in the partially plasticized or doughy state, it is possible to shoot the fixing parts into the closed base structure of the support, preferably of the corresponding plastic material, in order in this way to achieve virtually one-piece fixing. But preferably provision can be made such that an inherently strong support structure for passage of the stem-like fixing elements is provided with recesses, between which, to hold the respective intermediate element, there extend at least partially transverse recesses which discharge on the support structure into the open. In this configuration the support structure is then already completely extruded or injected with its indicated recesses and the fixing parts are then placed as a finished component, into the support structure in the manner of a shot. In this respect it would also be possible to introduce the fixing parts still partially plasticized into the support structure and to ultimately cure them only there.

In this process the support structure on its front side then is provided with a plurality of fixing elements in the manner of a “porcupine structure” and, insofar the product produced in this way can be used as an intermediate product for possible additional production processes. But preferably provision is made so that under heat or pressure the free stem ends of each fixing element are provided with a head or hook structure to produce a mushroom-shaped or hook-shaped fastener element which, with the corresponding loop material or nonwoven of a corresponding fastener element, forms a touch-and-close fastener part. In the implementation of a mushroom-like structure for the fixing elements it is then also possible to allow them to interact with a corresponding mushroom fastener material in which the mushrooms of one fastener part detachably engage the intermediate spaces of the mushroom material of the other fastener part for closing the fastener.

In the device according to the invention for implementing the indicated process, said device is provided with a feed part which supplies the cramp-shaped, in particular U-shaped, fixing parts as a whole to the support plate in a forward-pointed supply position and can be provided with another fixing part in a rear magazining position. Similarly to a shooting apparatus the cramp-shaped fixing part is then moved out of the magazining position into the supply position and hence the fixing part is shot into the support structure at each respectively provided position.

Other advantageous embodiments of the solution according to the invention are the subject matter of the other dependent claims.

The process according to the invention and a device for implementing the process will be detailed below using an embodiment as shown in the drawings. In this context the figures are schematic and not to scale.

FIG. 1 shows the basic structure of the production device,

FIGS. 2 and 3 show in a perspective front view a plate-like support structure, once without, once with the stem-like fixing elements,

FIG. 4 shows a section along line I-I in FIG. 1 for one recess of the support structure,

FIG. 5 shows a side view of a U-shaped fixing element,

FIG. 6 shows a section along line II-II in FIG. 7 with the connecting means attached to the rear,

FIG. 7 shows a backward perspective of a closing plate, viewed in direction B of looking at the article of FIG. 6, but without the pin-like connecting means.

The process according to the invention is used to produce a fixing means as is shown not yet completed in FIG. 3 by way of example. This fixing means which is made, for example, as a touch-and-close fastener part can be a component of a touch-and-close fastener, as has become known under the trademark “Kletten” [hook and loop fastener]. The process according to the invention presupposes first of all the formation of a support structure 10 which is provided with stem-like fixing elements 12 (cf. FIGS. 1, 3 and 5). As shown in particular by FIG. 5, these stem-like fixing elements 12 are connected integrally to one another in pairs on their base side by way of a transversely running intermediate element 14. In this way a cramp-shaped, in particular U-shaped, fixing part 16 as a whole is formed, essentially (not detailed) a fixing part 16 could also have more than two stem-like fixing elements 12 in the form of a multi-pronged body in which the other fixing element could be connected transversely to the figure plane of FIG. 5 to the intermediate element 14, for example to another intermediate element which emerges from the plane of the drawing. However, the solution according to the invention will be detailed below using the two-pronged structure as shown in FIG. 5.

The respective fixing part 16 can be made rather U-shaped as shown in FIG. 1, but also V-shaped; however, a configuration as shown in FIG. 5 is preferred in which the two projecting stem-like fixing elements 12 undergo transition at a right angle into the intermediate element 14. Also, in the initial state of product manufacture, the free ends 18 of the fixing elements 12 are not yet reshaped so that the fixing elements 12 overall form cylindrical extensions. As the representation of the device shown in FIG. 1 illustrates, these fixing parts 16 magazined on top of one another are guided in a magazine position 20, for the sake of a simpler representation, the stack arrangement viewed only in the direction of looking at FIG. 1 being shown for the above illustrated stack of fixing parts 16. From the lower magazine position 20, a cramp-shaped, in particular U-shaped, fixing part 16 can be removed by means of a tongue-shaped feed part 22 and fed onto the support plate 10 along the axial direction X into a supply position which is not detailed. With the feed part 22 set back into the magazine position 20, as shown in FIG. 1, a magazined fixing part 16 can then descend and it reaches the position as shown in FIG. 1 in which again supply to the support plate 10 is possible. In this way the feed part 22 moves forward and backward for a production sequence as shown by the arrow A in FIG. 1.

The plate-shaped support structure 10 for penetration of the stem-like fixing elements 12 is provided with recesses 24 in a double-hole arrangement (see cross section as shown in FIG. 4) between which a transverse depression 26 extends in pairs to hold the intermediate element 14 of the fixing part 16 and discharges into the open on the free rear of the support structure 10. As is especially to be seen in FIG. 4, this transverse recess 26 stands vertically on the two recesses 24 which are positioned a certain distance from each other. In order to achieve good introduction of the cramp-like fixing parts 16 originating from the rear 28 of the support structure 10, the transverse recess 26 widens by means of conically running boundary walls 30, which, for the purpose of guidance, discharges less steeply into a conical intermediate wall region 32 of the longitudinal recesses 24, which in turn towards its free end, which discharges on the front 34 of the support structure 10, has a cylindrical, stabilizing shoulder for the free end region of the two fixing elements 12. In this way, with the indicated recesses 24, 26, “threading” of the fixing elements 12 into the support structure 10 is achieved and furthermore after completed fixing the fixing part 16 is reliably pre-positioned on the support structure 10.

So that the supply means (feed part 22) can provide all the recesses 24, 26 present in the support structure 10 with assignable cramp-like fixing parts 16, control of the support structure 10 is necessary such that it can be moved in directions perpendicular to one another according to the double arrows Y and Z in order in this way to achieve supply via line X to the respective opening in the support structure 10. It would also be possible, with the plate at rest, to move the supply means or to secure both the support structure and also the supply means analogously for outfitting the support structure 10 with fixing parts 16. The supply means shown in FIG. 1 with a feed part 22 can, in a shot-like sequence, provide the support structure 10 with fixing parts 16 with high target precision so that not only can a very rapid production process be implemented, but also process faults and scrap rates are reduced. The described production process therefore can be operated very economically. Also several shooting apparatus which are not shown can be used for one or more support structures 10 in juxtaposition.

When all the fixing parts 16 have been introduced into the support plate as the support structure 10, the free stem ends 18 as shown in FIG. 3 project above the front side 34 of the support structure 10. This front side can be provided as shown in FIGS. 2 and 3 with a rectangular, in particular square placement field; but other geometrical configurations are also conceivable here. In particular the support structure 10 can be made as a film-like belt or the like. If the stem-like fixing elements as shown in FIG. 3 are to be provided on the end side with an interlocking element, such as, for example, an interlocking mushroom 36 (cf. FIG. 5), it is sufficient to heat or singe the free ends 18 of the stems 12 and as a result of the surface tension of the plastic material they then form a head structure analogous to the interlocking mushrooms 36 as shown in FIG. 5. In addition or alternatively, there can also be an independent molding means (not shown) which induces shaping for the free ends 18 of the stem 12, so that in this respect, in addition to the mushroom-like structures, formation of conventional fastener hooks or the like would be possible. Since these production process steps are known, for example, by FIGS. 3 and 4 of EP 1 047 539 B1 in addition to the respective text sites, they will not be further detailed here. Basically, however, it is also possible to deliver the fastener means as shown in FIG. 3 without the interlocking elements as an intermediate product to the further processing industry for possible further use.

So that the indicated fixing parts 16 do not again unintentionally leave the support structure 10 with its recesses 24, 26, for example, by falling out, they are cemented in the openings of the support plate 10 to the latter by means of a suitable adhesive material. But it is also possible, as shown in FIGS. 7 and 8, by means of a termination plate 38, to clip them via clip connection means 40 with clip connections 42 which are attached on the edge side opposite in the wall region of the support structure 10 (cf. FIGS. 2 and 3). By preference provision is made so that the fixing parts 16 be cemented both in the support structure 10 and also the closing plate 38 be seated in addition, in particular to form a clean termination to the exterior.

This support plate 38, as is shown especially in FIG. 6, can be provided to the rear with at least one connecting means 44 which enables locking of the combination of the closing plate 38 with the support structure 10 on third parts, for example, on vehicle parts, with at least two opposite catch parts 46. In this way the fixing means can be applied in the manner of an island to the roof area of a motor vehicle on which then the head liner could be reliably fixed stationary by means of the corresponding fixing elements, for example, in the form of loops—attached to the head liner—with the formation of a touch-and-close fastener part.

It is still within the scope of the invention to make the support structure 10 partially plasticized without recesses 24, 26 in order to then shoot the fixing parts 16 permanently into the structure of the support plate in the manner of shot cramps. Furthermore it is possible to produce double-acting touch-and-close fastener parts if, as is not shown, the fixing parts 16 are shot from the two sides into assignable recesses so that they can project with their free end regions 18 both on the front side 34 and also on the back side 28.

Instead of the device as shown in FIG. 1, it can furthermore be provided that the respective fixing part 16 be obtained from a plastic monofilament element which is supplied in the form of a line or thread from a storage means (not shown) of a shaping zone to the supply means which then first reshapes the monofilament wire into the cramp-shaped fixing part 16 in order then in the next step to enable introduction of the fixing part into the support structure 10. In this configuration as well very high production rates can be achieved. It goes without saying that when a support structure 10 is equipped with the fixing parts 16, it leaves the feed device and a new support plate as the support structure 10 is supplied to the feed with the fixing parts 16. In this respect, the use of a magazining means is then unnecessary.

With the device according to the invention and the respective process, preferably thermoplastic materials can be easily processed, the plate-like support structure 10 preferably consisting of a material which is easily subjected to injection-molding. But essentially it is also possible to provide a metal mold blank with cramp-like fixing parts 16 consisting of easily processed plastic, such as for example polypropylene or polyamide, or of an easily moldable metal material. 

1. A method for producing a fixing means, for example, in the form of a touch-and-close fastener part, comprising the following: formation of a support structure (10) which is provided with stem-like fixing elements (12) which are connected to one another at least in pairs by way of an intermediate element (14) with the formation of a cramp-shaped, in particular U-shaped, fixing part (16), the stem-like fixing elements (12) extending through the support structure (10) and projecting over it and the intermediate element (14) extending between these fixing elements (12) being located on the support structure (10), characterized by the introduction of the respective fixing part (16) as a whole into the support structure (10) which is made cramp-shaped, in particular U-shaped, for this purpose as a molded part before introduction.
 2. The process according to claim 1, wherein the support structure (16) for passage of the stem-like fixing elements (12) is provided with recesses (24), between which, to hold the respective intermediate element (14), transverse recesses (26) extend which discharge on the support structure (10) into the open.
 3. The process according to claim 1, wherein at least in part the free ends (18) of the stem-like fixing elements (12) are heat-treated and/or mechanically reshaped with the formation of head-like or hook-like fastener elements (36).
 4. The process according to claim 1, wherein the cramp-shaped, in particular U-shaped, fixing parts (16) are melted, cemented and/or clipped to the support structure (10) with formation of a combination.
 5. The process according to claim 1, wherein the support structure (10) is made plate-like and is provided with a closing plate (38), in particular clipped.
 6. The process according to claim 5, wherein the termination plate (38) at least on its side facing away from the support structure (10) is provided with at least one connecting means (44).
 7. The process according to one of claim 1, wherein in particular for the support structure (10) a thermoplastic material is used which can be processed in an injection molding process and wherein the respective fixing part (16) is formed from a plastic monofilament, preferably from a polyamide or polypropylene filament.
 8. A device for implementing the process according to one of claim 1, wherein it has a feed part (22) which supplies cramp-shaped, in particular U-shaped, fixing parts (16) as a whole to the support structure (10) in a forward-directed supply position and which can be provided in a backward magazining position (20) with another fixing part (12).
 9. The device according to claim 8, wherein it is provided with a shaping means which forms the cramp-shaped, in particular U-shaped, fixing parts (16) from a straight plastic monofilament which can then be supplied to the support structure (10) by means of the feed part (22). 